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Population

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Population – PowerPoint PPT presentation

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Title: Population


1
Population Development in Urban
Environments Botkin Keller Chapter 29
2
Who Cares?
  • About 75 of the U.S. population now lives in an
    urban area, and there is growing interest in
    revitalizing U.S. cities. We have seen this in
    the downtown renewal projects here in Tucson.
  • Globally, about 45 of the total population is
    urbanized and the percentage is expected to grow
    to 62 by 2025. Economic development leads to
    urbanization.
  • About 75 of people in developed nations are
    urbanized compared to only 38 in developing
    nations.
  • By 2015 there will be 36 megacities with
    populations exceeding 8-10 million, most of them
    will be in Asia.
  • Urban areas present ecological challenges, but
    they also present opportunities.

3
Urbanization
4
Megacities
MOST MEGACITIES ARE LOCATED IN THIRD WORLD
5
(No Transcript)
6
Largest Cities as of 03/2010
Rank City Population
1 Shanghai (China) 13,831,900
2 Mumbai (India) 13,830,884
3 Karachi (Pakistan) 12,991,000
4 Delhi (India) 12,565,901
5 Istanbul (Turkey) 11,372,613
6 São Paulo (Brazil) 11,037,593
7 Moscow (Russia) 10,508,971
8 Seoul (South Korea) 10,464,051
9 Beijing (China) 10,123,000
10 Mexico City (Mexico) 8,841,916
7
Largest Mega-Regions 03/2010
  • The biggest mega-regions, which are at the
    forefront of the rapid urbanisation sweeping the
    world, are
  • Hong Kong-Shenhzen-Guangzhou, China, home to
    about 120 million people
  • Nagoya-Osaka-Kyoto-Kobe, Japan, expected to grow
    to 60 million people by 2015
  • Rio de Janeiro-São Paulo region with 43 million
    people in Brazil.
  • The same trend on an even larger scale is seen in
    fast-growing "urban corridors"
  • West Africa 600km of urbanisation linking
    Nigeria, Benin, Togo and Ghana, and driving the
    entire region's economy
  • India From Mumbai to Dehli
  • East Asia Four connected megalopolises and 77
    separate cities of over 200,000 people each occur
    from Beijing to Tokyo via Pyongyang and Seoul.

8
Regional Urban Growth
9
Urbanization Summary
  • MEGAcities Cities with over 8-10 million
    population Definitions vary
  • Rank Size Rule (George Zipf) Hierarchy of
    Cities
  • If all the settlements of a country are ranked
    according to population size, the sizes of
    settlements will be inversely proportional to
    their rank
  • OR
  • Second largest town or city is half the size of
    the first size, the third would be a third the
    size etc.
  • Primate Cities (Mark Jefferson) Cities much
    larger than other cities in country (e.g. Seoul
    34 x Pusan)

10
Germany Does this fit the Rank Size Rule?
  • RANK SIZE RULE EXPECTATIONS
  • 1 Berlin 3 390 000
  • 2 Hamburg 1 195 000
  • 3 München 1 130 000
  • 4 Köln 847 500
  • 5 Frankfurt 678 000
  • 6 Essen 565 000
  • 7 Dortmund 484 000
  • 8 Stuttgart 424 000
  • ACTUAL POPULATION
  • 1 Berlin 3 390 000
  • 2 Hamburg 1 700 000
  • 3 München 1 300 000
  • 4 Köln 965 000
  • 5 Frankfurt 640 000
  • 6 Essen 590 000
  • 7 Dortmund 589 000
  • 8 Stuttgart 587 000

11
Peru Does this fit the Rank Size Rule?
  • ACTUAL POPULATION SIZE
  • 1 Lima 7 000 000
  • 2 Arequipa 700 100
  • 3 Trujillo 600 000
  • 4 Chiclayo 470 000
  • 5 Iquitos 335 000
  • 6 Piura 310 000
  • 7 Huancayo 305 000
  • 8 Chimbote 300 000
  • RANK SIZE RULE
  • 1 Lima 7 000 000
  • 2 Arequipa 3 500 000
  • 3 Trujillo 2 333 000
  • 4 Chiclayo 1 750 000
  • 5 Iquitos 1 400 000
  • 6 Piura 1 166 000
  • 7 Huancayo 1 000 000
  • 8 Chimbote 875 000

What type of city is Lima?
12
Third World Urbanization
  • Urbanization Level
  • Latin America gt Asia gt Africa
  • Exception China and India in Asia
  • Urbanization Rate
  • Africa, Asia gt Latin America

13
Migration
  • Migration components
  • Rural to Urban
  • Urban to Urban
  • Circulators
  • Why migrate?
  • Lure of big city
  • Job opportunities (pull factor)
  • Lack of rural opportunities (push factor)

14
The City as a System
  • A city influences and is influenced by its
    environment
  • A city must
  • Maintain a flow of energy
  • Provide necessary material resources
  • Have ways of removing waste
  • Accomplished though transportation and
    communication with outlying areas

15
The City as an Ecological System
  • Cities need to be understood as ecological
    systems.
  • Complex systems of social networks and resource
    supply networks (food, water, energy, products).
  • Not a self-sustaining system as it requires
    inputs for the surrounding countryside.
  • They must supply products.
  • QUESTION How is the city like an organism?

The average city resident in an industrial
country uses annually about 208,000 kg of water,
660 kg of food, and 2,1466 kg of fossil fuel and
produces 1,660,000 kg of sewage, 660 kg of solid
waste and 200 kg of air pollutants.
16
Importance of Site and Situation
  • The location of a city is influenced by
  • Resources, transportation, politics
  • Site the local environment of the city. That is
    it is the summation of all environmental features
    of that location. Can be modified by people
    Example Pumping water out of New Orleans
  • Situation the placement of a city in respect to
    other areas and resources
  • Example Fall Line (next slide)

New Orleans Poor Site, important situation.
NY has a much better site
17
New Orleans
New Orleans (Before - on 9 March 2004) with
Superdome near the center.
New Orleans (After - on 31 August 2005) with now
damaged Superdome. 
  • Should it be rebuilt?

You decide Read pages 622-624 for information.
18
Sinking Venice
  • Should it be saved?

You decide Read page 627 for information.
19
Fall Line
A fall line occurs on a river where there is an
abrupt drop in elevation, creating waterfalls or
rapids. The mid- and south-Atlantic states have a
fall line that separates the Piedmont from a
broad coastal plain. It is along the fall line
that waterpower is available and where most of
our important colonial cities developed. Example
Washington D.C. is built near the fall line of a
major river (The Potomac River)
Page 628
See page 629 for clarification.
20
The History of Cities
  • 4 Stages
  • The rise of towns
  • Development of agriculture
  • The era of classic urban centers
  • Development of transportation
  • The period of industrial metropolises
  • Industrial Revolution
  • Urban Sprawl with modern transportation - LA
  • The age of mass telecommunication, computers and
    new forms of travel
  • Development of telecommunication

For more information see page 630
21
City Planning for Defense and Beauty
  • City Planning
  • Formal, conscious planning for new cities
  • 2 themes of city planning defense and beauty
  • Knowledge of urban ecology is paying off in the
    design of new cities.
  • Woodlands, TX is an example. The city was
    designed so that the homes and roads were on
    ridges, and the lowlands were left as natural
    open space for the temporary storage of
    floodwater. The lowlands also provide habitat
    for flora and fauna, and is aesthetically
    pleasing.
  • Frederick Law Olmsted
  • One of the most important modern experts on city
    planning
  • Designed Central Park in New York.
  • Created the fens in Boston to help control
    water pollution.

22
The City as an Environment I
  • Energy budget
  • Urban atmosphere and climate
  • For example, a city alters the energy budget of
    its landscape by modifying the absorption and
    reflection of solar energy, evaporation of water,
    conduction of air, wind, convection of water, and
    combustion of fuel. Consequently, the local
    climate is modified. Cities are warmer than
    surrounding areas (heat island effect).
  • Solar energy
  • Use of solar energy for heating was once common,
    but was replaced by cheap fossil fuel. It is now
    coming back in some places.

23
Urban Atmosphere and Climate
24
The City as an Environment II
  • Water
  • Cities have a large impact on the water cycle by
    increasing the amount of impervious surface, and
    therefore runoff. Storm sewers collect runoff.
    This decreases infiltration and ET, which
    decreases evaporative cooling and humidity. Many
    cities now are discouraging the spread of new
    impervious surfaces. This is done sometimes by
    setting a tax rate proportional to the amount of
    impervious surface area. Cities also are using
    artificial wetlands to hold runoff, which serves
    three purposes water treatment, decreased
    runoff, and aesthetics. Cities also can have
    higher rainfall amounts, fog and cloud cover
    because dust particles in the air serve as
    condensation nuclei.
  • Soils (made lands)
  • Many cities are build on flood plains, which
    often requires the construction of levees to
    protect against river flooding. The levees affect
    the hydrology of the entire river, and worsen the
    flooding along other unprotected sections of the
    river. An alternative is to use the floodplain
    for parks or for multiple uses that can tolerate
    periodic flooding. Example Near San Francisco
    (in Berkeley a marina park is built on a
    solid-waste landfill.

25
The City as an Environment III
  • Pollution
  • Urban soils are highly modified by pavements and
    toxic substances like heavy metals. Many urban
    soils are 'made land' or sols made from fill.
    Fill soil is unconsolidated and vulnerable to
    shaking from earthquakes.
  • Some areas are built on top of waste landfills,
    such as the marina park in San Francisco.
  • Everything in a city is concentrated, including
    pollutants. Urbanites are exposed to more kinds
    of toxic chemicals in higher concentrations and
    more noise than their rural counterparts, and the
    average lifespan of urbanites is shorter.
    Pollution sources include motor vehicles,
    stationary power sources, home heating, and
    industry. It is impossible to eliminate exposure
    to pollutants, but exposure can be minimized
    through proper urban planning.
  • The American city with the highest number of
    early deaths due to pollution is LA, followed by
    New York, Chicago, Philadelphia and Detroit.

26
Bringing Nature to the City I
  • Cities favor certain animals and plants
  • With the exception of some birds and small
    mammals (e.g. squirrels), most forms of wildlife
    in cities are considered pests. There are species
    that cannot persist in urban environments and
    disappear, species that tolerate urban
    environments but do better elsewhere, and species
    that thrive in urban environments. Species that
    do too-well become pests. Many animals adapt to
    urban environments and manage to find suitable
    habitat and alternative foods (e.g. road kill).
    There are species that are very beneficial such
    as the peregrine falcon that now nest on
    skyscrapers and prey on pest species. Cities can
    be better managed to encourage the beneficial
    wildlife species. Pests include insects, birds,
    and mammals. Some can spread disease. The Bubonic
    plague, spread by fleas found on rodents is an
    example. The best was to control them is using
    knowledge of their urban ecology to identify and
    exploit their vulnerabilities.
  • Food webs tend to be LESS complex in cities

27
Bringing Nature to the City II
  • Trees are important to urban environments
  • The use of trees provides not only aesthetics but
    benefits the microclimate. However, the
    vegetation in cities must be carefully selected
    to tolerate the different kinds of stresses that
    an urban environment imposes, including pollution
    and drought stress.

28
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29
Bringing Nature to the City III
  • Cities help conserve biological diversity
  • Bringing nature into the city can be a practical
    problem. Riparian cities can integrate
    waterfront, which is a natural magnet for people
    and has helped with the renewal of a number of
    cities from Austin to Providence.
  • Parks, preserves and zoos in cities have become
    some of the worlds best wildlife habitats.
    Example Central Park
  • Some endangered species do well in the city
    environment. Example Falcons
  • City yards can become great wildlife sanctuaries.
    See scrAPES stepup!
  • Urban drainage can become great habitats! (see
    next slide)

30
Planned for Better Drainage
31
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32
Why Urbanize?
  • Urbanization Economic Growth (?)
  • Agglomeration Localization Economies
  • Potential Markets
  • Exception Africa
  • Rural Urban Linkages
  • Symbiotic Economic Relationship

33
Why not urbanize?
  • Is Urbanization Good?
  • Urban Bias (Michael Lipton)
  • Political and Economic Domination of urban groups
  • Lopsided development, more favorable to urban
    areas
  • Anti-Urban Policies
  • Ujaamization (Tanzania, Julius Nyerere)
  • Cultural Revolution (China, Mao Tse-Tung)
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